package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.FOLLOW_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userservice;
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        if(UserHolder.getUser() == null){
            return Result.fail("请先登录");
        }
        Long userId = UserHolder.getUser().getId();

        String key = FOLLOW_KEY + userId;

        if(isFollow){
            //关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            if (save(follow)) {
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else{
            //取消关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean remove = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if (remove) {
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId)
                .eq("follow_user_id", followUserId)
                .count();

        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long followUserId) {
        // 获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key = FOLLOW_KEY + userId;
        String key2 = FOLLOW_KEY + followUserId;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        List<Long> list = intersect
                .stream()
                .map(Long::valueOf)
                .collect(Collectors.toList());

        List<User> users = userservice.listByIds(list);

        List<UserDTO> userDTOList = users
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(userDTOList);

    }
}
